Usually the costs of something rise as you do or have more of it, while its benefits fall. So unless the cost of the first unit is already very high or the benefits of the first unit are already very low there is some amount greater than zero that it is optimal to have or do. This is true for an individual and for a society. The first car you have massively changes your life. The second one adds pleasure, variety, and a good deal of practicality in some situations, but it's much less useful than the first. Nearly no one has three cars to themselves because the benefits are vanishingly small and the cost is rising for storage, upkeep reasons.

The first few million cars in a society the size of the UK are amazingly useful, the next million go to people who don't need them as much but do add to congestion, pollution and so on. The forty-millionth or sixty-millionth car starts taking up way more space than it's worth.

Well as the title suggests I think it's possible we might be approaching (or already have gone past) this point when it comes to smoking regulation. I wrote before about how plain packaging was probably a mirage (incidentally I learned today that the UK would drop three whole places, from 2nd to 5th on the GIPC's index of intellectual property rights protections if it passed it; though many of this blog's readers probably wouldn't mind that).

We may have needed very activist laws in the past because it really is quite difficult to inform people about anything really, and smoking is dangerous in important ways such that if you don't understand the decision you're taking you really could make your life a lot worse. But nowadays people may well even overestimate the costs and people are thus taking the right decisions to maximise social utility. It isn't a question of externalities because smokers actually cost the state less by dying earlier (a bad thing!)

This isn't just a musing. A new paper in the Journal of Cost-Benefit Analysis ("Retrospective and Prospective Cost-Benefit Analysis of US Anti-Smoking Policies" (pdf) by Lawrence Jin, Donald S. Kenkel, Feng Liu & Hua Wang) says roughly the same.

We use a dynamic population model to make counterfactual simulations of smoking prevalence rates and cigarette demand over time. In our retrospective BCA (Benefit-Cost Analysis) the simulation results imply that the overall impact of antismoking policies from 1964 – 2010 is to reduce total cigarette consumption by 28 percent.

At a discount rate of 3 percent the 1964-present value of the consumer benefits from anti-smoking policies through 2010 is estimated to be $573 billion ($2010). Although we are unable to develop a hard estimate of the policies’ costs, we discuss evidence that suggests the consumer benefits substantially outweigh the costs.

We then turn to a prospective BCA of future anti-smoking FDA regulations. At a discount rate of 3 percent the 2010-present value of the consumer benefits 30 years into the future from a simulated FDA tobacco regulation is estimated to be $100 billion. However, the nature of potential FDA tobacco regulations suggests that they might impose additional costs on consumers that make it less clear that the net benefits of the regulations will be positive.

Especially cool is the chart of a rational level of cigarette smoking, based on the benefits to the smoker of fulfilling their preferences vs the costs of frustrating their preferences for better health and a longer life.

I'm not saying that this research is conclusive. One paper is one paper. But I think it's getting to the point where further cigarette regulation is becoming intrusive and costly without necessarily producing large benefits to its purported targets. We should consider if we've maybe hit the cigarette regulation sweet spot.